Centering device for punch presses



Jan. 14, 1964 w. PEDDINGHAUS 3,117,480

CENTERING DEVICE FOR PUNCH PRESSES Filed Nov. 28. 1960 2 Sheets-Sheet 1 IN V EN TOR.

Jan. 14, 1964 w. PEDDINGHAUS 3,117,480

CENTERING DEVICE FOR PUNCH PRESSES Filed NOV. 28, 1.960 2 Sheets-Sheet 2 IN VEN TOR.

3,117,430 CENTERING DEVICE FQR PUNCH PRESSES Werner Peddinghaus, Gevelsherg, Westplraiia, Germany,

assignor to Paul Ferd. Peddinghaus, Gevelsherg, Westphalia, Germany Filed Nov. 28, 1960, Ser. No. 72,216 Claims priority, application Germany Dec. 1, 1959 6 Claims. (Cl. 83-520) The present invention relates to a centering and setting device especially for punch presses and, more specifically, concerns a device for centering or setting a point on a work piece below the punch of a punch ress.

p When punching metal sheets or profiles, generally the center point of the hole to be punched is punch marked or is indicated by otherwise marking the work piece. The punch for producing the hole has a dead center which must be directed toward the marked center point for the hole. in order to obtain a precise punching, it is necessary to move the center point, i.e. the metal sheet or the profile, until the dead center point of the punch and the marked center point for the hole are precisely in alignment with each other. To this end, the punch is provided with a lever system by means of which the punch may be lifted and lowered in order to verify the alignment of dead point and marked center point. This verification of the alignment of the said two points is frequently rather'difiicult, especially when the punch more or less covers the marked center point. Considering further that the alternating lowering of the punch and displacement of the frequently heavy metal sheet and profiles is rather time consuming and fatiguing, the heretofore known method of centering and setting must be considered rather cumbersome.

It is, therefore, an object of the present invention to provide a centering or setting device which will overcome the above mentioned drawbacks.

It is another object of this invention to provide a centering or setting device, particularly for punch presses, which will make possible a fast and precise centering or setting without the necessity of lowering the punch for purposes of verifying the alignment.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

FIG. 1 illustrates a side view of a device according to the invention.

FIG. 2 is a top view of the device shown in FIG. 1 while the punch has been omitted.

'FIGS. 3 and 4 illustrate the geometric relationship of the widths of the light bands or light beams.

According to the embodiment illustrated in FIGS. 1 and 2, the die It is supported by a die holder 20 which latter has a holder 21 extending upwardly behind the punch. Provided on the last mentioned holder there is a curved yoke 22 journalled in correspondingly curved groove 23 (FIG. 2). This yoke may be clamped fast in the curved groove 23, which constitutes guiding means therefor, by screws 24, 25 in its selected position while a loosening of the screws will permit said yoke to be lifted out of said groove whenever desired. The yoke may be displaced in the direction of the double arrow 26.

At the end of yoke 22 there are provided light sources 27, 28 which are formed by an electric incandescent lamp and the outer cylindrical supports 29, 30. Electric conductors 31, 32 lead to the outer cylindrical supports 29, 30. The front end of said supports is covered by covers 33, 34 provided with slots 35, 36 through which the light bands 37, 38 may be passed to the outside.

The light sources 27, 28 are arranged at the end of 3,117,480 Patented Jan. 14, 1954 yoke 22 in two axial planes of the punch located at a right angle with regard to each other. The said light sources are furthermore so designed that the light bands 37, 38 intersect on a line 39 (FIG. 3). This line corresponds to the central axis or extension thereof of the punch 1 of FIG. 1. When hitting a horizontal support, for instance a work piece on the die, an illuminated cross mark (FIG. 2) is formed when the angle of inclination of the light sources 27, 28 is selected properly.

As will be evident from FIG. 3, the light bands 37, 38 intersect on line 39 between the points 40 and 41. If the surface of the work piece to be punched is located in point 41, an angle of light will appear on the work piece. A similar angle of light but with oppositely directed angle opening will then appear on the surface of the work piece if the latter is located in point 40. If the surface of the work piece is located between the two points 40 and 41, an illuminated cross mark will be formed.

For purposes of determining the width of the light bands in conformity with the thickness of the metal sheet to be punched, the arrangement of FIG. 4 may be employed. Geometric considerations show that with a difference a in the thickness of the metal sheets (distance between points 4t) and 41), the width b of the light bands 37. 33 is to be selected according to the formula.

angle a corresponding to the angle of incidence between light beam and horizontal surface of the work piece.

If the punch is suitable for punching work pieces of a thickness of 3 to 12 millimeters (difference 9 millimeters), an adjustment of the light source will not be necessary if the widths b of the light beams are selected as cosine at times 9. I

It is, of course, to be understood that present invention is, by no means, limited to the particular constr'uctions shown in the drawings but also comprises any modifications within the scope of the appended claims.

What I claim is:

1. In a centering device, especially for use in connection with punch presses: supporting means a punching tool axially movable relative to said supporting means for selective movement from a retracted position into a punching position and vice versa, and two light sources supported by said supporting means in respective planes intersecting in the punching tool axis at right angle to each other and said sources being arranged to throw intersecting light beams at an angle to and intersecting the extension of the longitudinal axis of said punching tool at a point spaced from said punching tool when the latter occupies said retracted position and located in the path of movement of said punching tool for carrying out a punching operation, each light source comprising a closed cylinder and a lamp fixed in said cylinder and a vertical slot in the end of the cylinder toward said punching tool axis, and a holder holding said cylinders in said planes and being mounted in said supporting means and being adjustable therein for moving said cylinders in unison in a plane normal to the punching tool axis while the relation of the cylinders to the punch axis is being maintanied.

2. In a centering device, especially for use in connection with punch presses: Supporting means, a punching tool axially movable relative to said supporting means for selective movement from a retracted position to a punching position and vice versa, a holder in the form of a bar curved so as to be concentric with the punching tool axis disposed in a plane normal to the punching tool axis and supported on said supporting means for adjustment thereon along the arc of curvature of said holder, and two light sources supported by said holder at op- I 3 posite ends thereof and at different sides of said punching tool and respectively arranged at an angle of the same magnitude with regard to the extensionof the longitudinal axis of said punching tool while being so arranged as respectively to throw two light beams intersecting along the extension and lying in (respective mutually perpendicul ar planes which intersect in said axis.

3. A centering device according to claim 2, in which said light sources are so designed as to respectively throw a light beam of band shape.

4. In a centering device, especially for use in connection with punch presses: supporting means, a punching tool axially movable relative to said supporting means for selective movement from a retracted position into a punching position and vice versa, a holder in the form of a bar curved so as to be concentric with said punching tool axis disposed in a plane normal to the punching tool axis and supported on said supporting means for adjustment thereon along the arc of curvature of said holder, and two light sources supported by said holder at different ends thereof and anranged on opposite sides of said punching tool, said light sources being arranged to throw band shaped light beams at an angle of the same 'magnitude, said light beams intersecting along the extension of the longitudinal axis of said punching tool and lying in respective mutual perpendicular planes which intersect in said axis, the region of intersection of said band-shaped light beams covering the range of the maximum thickness of the work pieces to be punched, said region of intersection of the light beams being located in spaced relationship to said punching tool when the 4% portion of the punching tool axis normally occupied by a workpiece to be punched.

6. In a centering device, especially for use in connection with punch presses: supporting means, a punching tool axially movable, relative to said supporting means for selective movement from a retracted position to a punching position and vice versa, die holder means for holding a die to receive the work piece to be punched, said die holder means being provided with guiding means in a plane normal to the punching tool axis and concentric with the punching tool axis, light source holder means in the form of a bar curved to fit said guiding means and disposed therein, said holder means being adjustable in said guiding means in the direction of the length thereof, and two light sources supported by said holder means at diflferent ends thereof and arranged to throw two light beams intersecting each other along the extension of the longitudinal axis of said punching tool and lying in respective mutually perpendicular planes which. intersect in said axis and said light beams intersecting at a level spaced from said punching tool when the latter occupies said retracted position and arranged in the path of movement of said punching tool from said retracted position into punching position, each light source comprising a closed cylinder, a lamp fixed therein, and a slot in the end of the cylinder nearest said punching tool axis disposed in a vertical plane.

' References Cited in the file of this patent VUNITED STATES PATENTS 893,427 Bennett M 14, 1908 1,356,285 Hopper Oct. 19, 1920 1,388,110 Hallock Aug. 16, 1921 FOREIGN PATENTS 543,591 Great Britain Mar. 4, 1942 589,378 Great Britain June 18, 1947 

2. IN A CENTERING DEVICE, ESPECIALLY FOR USE IN CONNECTION WITH PUNCH PRESSES: SUPPORTING MEANS, A PUNCHING TOOL AXIALLY MOVABLE RELATIVE TO SAID SUPPORTING MEANS FOR SELECTIVE MOVEMENT FROM A RETRACTED POSITION TO A PUNCHING POSITION AND VICE VERSA, A HOLDER IN THE FORM OF A BAR CURVED SO AS TO BE CONCENTRIC WITH THE PUNCHING TOOL AXIS DISPOSED IN A PLANE NORMAL TO THE PUNCHING TOOL AXIS AND SUPPORTED ON SAID SUPPORTING MEANS FOR ADJUSTMENT THEREON ALONG THE ARC OF CURVATURE OF SAID HOLDER, 